PIEZO1 forms an adhesive-mechanosensitive complex with activated LFA-1 on T lymphocytes

Abstract In order to respond to infection, injury and stress, T lymphocytes must successfully migrate from the bloodstream into inflamed tissue in a process called the leukocyte adhesion cascade. Of these steps, blockade of adhesion has shown clear clinical benefit in autoimmunity, and the step of intraluminal crawling is of great potential clinical importance. In order to coordinate adhesion and crawling while in circulation, leukocytes must respond appropriately to complex hemodynamic forces, including shear stresses and erythrocyte driven margination against the venule walls. Therefore, we hypothesized that the mechanosensitive calcium channel PIEZO1, which is preferentially expressed in T lymphocytes, mediates T lymphocyte responses to force during adhesion and crawling. To test this hypothesis, we genetically ablated PIEZO1 in primary T lymphocytes from healthy human donors using CRISPR/Cas9, and observed crawling ability in vitro. In this assay, PIEZO1 knockout cells exhibited decreased crawling and disrupted morphology. Moreover, we performed immunofluorescence of PIEZO1 on chemokine-activated crawling T lymphocytes, which demonstrated that PIEZO1 redistributes to the contact zone of crawling cells in a pattern reminiscent of a high-affinity LFA-1 focal zone. Additionally, PIEZO1 colocalizes specifically with high affinity LFA-1. Using co-immunoprecipitation indicated that PIEZO1 preferentially associates with the alpha integrin subunit of LFA-1 in its active form, through a conserved amphipathic eight amino acid motif. Taken together, our data suggest that PIEZO1 contributes to coordination of T lymphocyte crawling via interaction with integrins, modulating the affinity state and turnover of LFA-1.